E. coli are typically found in the intestines of humans and animals. They are normally harmless, but some types of E. coli can cause illness. E. coli are known for their ability to rapidly undergo cellular reproduction, causing illness quickly.

Based on this information, which statement best describes E. coli?

A. E. coli are prokaryotic, multi-celled organisms because they are highly complex and can change to be damaging or beneficial.
B. E. coli are eukaryotic, multi-celled organisms because they are highly complex and can perform many functions.
C. E. coli are prokaryotic, single-celled organisms because prokaryotic cells can replicate very fast.
D. E. coli are eukaryotic, single-celled organisms because eukaryotic cells can replicate very fast.